Block #468,592

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/31/2014, 2:51:25 PM · Difficulty 10.4323 · 6,323,008 confirmations

2CC
Cunningham Chain of the Second Kind

A sequence where each prime is double the previous prime minus one.

Block Header
Block Hash
b981c2a184ec8d9044891f14e438c6c4528f01c908dfc15dae300482b8bbe011

Height

#468,592

Difficulty

10.432280

Transactions

4

Size

1.91 KB

Version

2

Bits

0a6ea9ec

Nonce

282,548

Timestamp

3/31/2014, 2:51:25 PM

Confirmations

6,323,008

Merkle Root

0cbdea41b29cfd6e73f5f035fb36f379dda03f62aa8952bb7830a2cd8d16a75c
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

8.555 × 10⁹⁷(98-digit number)
85553355150843121735…95247965836306588001
Discovered Prime Numbers
p_k = 2^k × origin + 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin + 1
8.555 × 10⁹⁷(98-digit number)
85553355150843121735…95247965836306588001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.711 × 10⁹⁸(99-digit number)
17110671030168624347…90495931672613176001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.422 × 10⁹⁸(99-digit number)
34221342060337248694…80991863345226352001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.844 × 10⁹⁸(99-digit number)
68442684120674497388…61983726690452704001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.368 × 10⁹⁹(100-digit number)
13688536824134899477…23967453380905408001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.737 × 10⁹⁹(100-digit number)
27377073648269798955…47934906761810816001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.475 × 10⁹⁹(100-digit number)
54754147296539597910…95869813523621632001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.095 × 10¹⁰⁰(101-digit number)
10950829459307919582…91739627047243264001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.190 × 10¹⁰⁰(101-digit number)
21901658918615839164…83479254094486528001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.380 × 10¹⁰⁰(101-digit number)
43803317837231678328…66958508188973056001
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the Second Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), p₂ = 2p₁ − 1, p₃ = 2p₂ − 1, …
Circulating Supply:57,576,744 XPM·at block #6,791,599 · updates every 60s
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